Answer:
A.producing changes in the genetic code
Explanation:
Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).
Answer:
B i hope this help
Explanation:
The cell membrane consists primarily of a thin layer of phospholipids which spontaneously arrange so that the hydrophobic "tail" regions are shielded from the surrounding polar fluid, causing the more hydrophilic "head" regions to associate with the cytosolic and extracellular faces of the resulting bilayer. This forms a continuous, spherical lipid bilayer approximately 7 nm thick, barely discernible with a transmission electron microscope.
The arrangement of hydrophilic and hydrophobic heads of the lipid bilayer prevent polar solutes (e.g. amino acids, nucleic acids, carbohydrates, proteins, and ions) from diffusing across the membrane, but generally allows for the passive diffusion of hydrophobic molecules. This affords the cell the ability to control the movement of these substances via transmembrane protein complexes such as pores and gates.
<span>The Excretory System</span>
Answer:
Description below
Explanation:
Alcionaceans (Alcyonacea) is an order of corals that belongs to the subclass Octocorallia, of the Anthozoa class. <em>Soft corals</em> are commonly called, since they do not produce skeletons of calcium carbonate, so they do not contribute to the construction of the reefs, although they inhabit them.
The so-called soft corals and leather or leather corals, mostly meaty in appearance, have microscopic crystals of calcite in their tissues called spicules, whose function is to give consistency to the animal's tissue, in the absence of a skeleton. The shape and distribution of the spicules are the main characteristics used in the identification of genera and species of octocorals.
In addition to soft corals, this order includes gorgonians, which replace the skeleton of hard corals, Scleractinia order, by semi-rigid structures composed of calcite and / or a substance they generate called gorgonin.